2.8 Duplicates along curve but with animation
One way, if you need a large number of identical items to follow each other along a curve:


Prepare supports for the final, visible objects that will make up your conveyor. These could be an Array of simple planes, given a Curve modifier. The supports will deform as they go round the curve, but it doesn't matter.....





In the Object tab, Duplication panel of the support array, set Duplication to 'Faces'
CtrlP parent your conveyor-plate object to your support array. It will be duplicated on every face, and follow the curve without distortion:




The plates can be animated by moving the support array along the dimension of the Curve modifier's deformation, and cycling.